In an OFDMA communication system, the time-frequency resources of the system are shared among a number of mobile stations. The base station assigns resources to mobile stations using an assignment message, which is transmitted as part of a control channel. It is known to define multiple control channel instances in a particular time period to increase scheduling flexibility and reduce the round trip time for hybrid automatic repeat request (HARQ) transmissions.
Unfortunately, the scheduling flexibility at the base station increases the processing burden at the mobile station. Further, in certain cases, the benefits previously described are not beneficial, due to the traffic type, scheduling algorithm, etc.